Texas geology is best categorized by starting with the largest area distinctions known as the physiographic provinces. This map shows you the provinces.
The Gulf Coastal Plains (red, orange and yellow) are composed of massive sedimentary deposits.
In uniformitarian (atheists and long-age creationists/agnostics) geology terms these deposits are "Quaternary" and "Tertiary" age ("Cenozoic"). For creationist geologists these include recent age sedimentary deposits (post primary catastrophic events / post ice age) but otherwise predominantly deeper sedimentary deposits of either the initial catastrophic period (eruptive to dispersive phases of the catastrophic flood period - aka "Noah's" flood and meteor/asteroid impacts; the "eruptive" to "dispersive" phases can be seen in the Tas Walker geologic model) or the post-flood catastrophic events as described by others (e.g. the Steven Robinson model).
In uniformitarian (atheists and long-age creationists/agnostics) geology terms these deposits are "Quaternary" and "Tertiary" age ("Cenozoic"). For creationist geologists these include recent age sedimentary deposits (post primary catastrophic events / post ice age) but otherwise predominantly deeper sedimentary deposits of either the initial catastrophic period (eruptive to dispersive phases of the catastrophic flood period - aka "Noah's" flood and meteor/asteroid impacts; the "eruptive" to "dispersive" phases can be seen in the Tas Walker geologic model) or the post-flood catastrophic events as described by others (e.g. the Steven Robinson model).
The Central Texas Uplift (purple) consists of a mound of igneous (ie granite) and metamorphic rock (ie schist; gneiss) surrounded by sedimentary deposits. These rocks are categorized as "Precambrian" to "Cambrian" (early "Paleozoic") formations (i.e. original continental crustal bedrock).
The Edwards Plateau (green) consists of massive hardened sedimentary deposits (rock) and includes a cavernous (cave forming) zone within the formation known as the "Edwards Limestone" formation. The Grand Prairie province (brown; Ft Worth area) also consists of sedimentary rocks similar to those found in the Edwards Plateau. The Edwards Plateau deposits are categorized as "Mesozoic" age (triassic, jurassic, cretaceous) in the uniformitarian model, or inundation phase of one of the catastrophic models.
The Basin and Range province (brown) includes volcanic mountains and sedimentary rock. Large flows of volcanic ash and thick deposits of volcanic debris flank the slopes of most former volcanoes. There is no current measurable seismic activity in this region. Eroded craters exist where cores of volcanoes collapsed.
The High Plains (pale brown) consist of recent age and older sedimentary soils and rock that are categorized as "Cenozoic" and "Mesozoic" in the uniformitarian model, or inundatory, recessive, and post ice-age phases of the catastrophic (creationist) models.
The North Central Plains (blue) consist of sedimentary deposits also known as "Permian" rocks. Some recent age deposits are identified but the materials are mostly categorized as "Paleozoic" age in the uniformitarian model, or biotic phase of creationist model.
The political boundary or county boundary map used by geologists and the oil and gas industry is presented below and is different:
The political boundary or county boundary map used by geologists and the oil and gas industry is presented below and is different:
